Flood Potential Outlook
Issued by NWS Grand Rapids, MI

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FGUS73 KGRR 032122
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MIC005-015-025-035-037-045-057-065-067-073-075-077-081-085-
105-107-117-121-123-127-133-139-159-021800-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
423 PM EST THU MAR 03 2016


...2016 SPRING FLOOD AND WATER RESOURCES OUTLOOK NUMBER 2...

This Spring Flood and Water Resources Outlook is for the rivers
in Southwest Lower Michigan.

...Flood Outlook Highlights...

The flood risk this spring is near to below normal. Much of the
region has below normal snowpack with little or no frost depth or ice
in the rivers.  The relatively wet seasonal conditions that occurred
have allowed for near to above normal soil moisture for much of the
region. River levels were largely above normal as a result. The
degree of flooding will largely be driven by the the rain events as
they happen during the spring.  With above normal soil moisture...the
runoff will be efficient to start the season.  A risk for periods of
rain...some of which could be heavy...suggests an elevated risk for
flooding next week depending on how the storm evolves.

...Flood Terminology...

The term minor flooding is used to indicate minimal or no property
damage.  However some public inconvenience is possible.

The term moderate flooding is used to indicate some inundations of
structures and roads near streams.  Some evacuations of people
and/or transfer of property to higher elevations may be needed.

The term major flooding is used to indicate exstensive inundation
of structures and roads.  Significant evacuations of people and/or
transfer of property to higher elevations will be needed.

...Probabilistic Outlook...

Southwest Lower Michigan has a near to below normal risk
for flooding this spring.


...Past Precipitation...

Precipitation across the area this past fall and winter was generally
above normal. The Muskegon...White and Pere Marquette basins saw over
125 percent of normal precipitation for the winter.  Snowfall has
been below average.

...River Conditions...

The river levels were near to above normal.  most rivers were ice
free.  If any ice existed it would likely be minimal.


...Soil Moisture and Frost Depths...

Soil moisture conditions were generally near normal across the
Southwest Lower Michigan. Although the Upper Muskegon basin
featured above normal values.  No Frost depth was noted for most of
the area.  Portions of the Muskegon and White River basins did have a
shallow frost depth of less than 2 inches.

...Snow Cover and Liquid Water Content...

Snow covered much of the region with depths ranging from around 2 to
8 inches with the most located in the Upper Grand basin. The liquid
water equivalents were generally under an inch but an area of over an
inch existed in the Upper Grand basin.   These values
represent mostly below normal liquid water equivalent amounts
for this time of the year.

...Weather Outlook...

A surge of gulf moisture next week could lead periods of rain...some
of which may be heavy at times...for Southwest Lower Michigan.
Uncertainty does exist on the track of the storm that eventually
pushes through so close monitoring will be needed.  at this point it
appears that most locations are forecasted to see less than 2 inches.
this...combined with snow melt would likely lead to some minor
flooding.   however a slight northward shift of the storm track could
cause greater rain amounts which would lead to more impactful
flooding.

The 6 to 10 day outlook calls for above normal temperatures and
precipitation. The 90 day outlook calls for an increased potential
for warmer than normal temperatures and below normal precipitation.



In Table 1 below...the current (CS) and historical (HS) or normal
probabilities of exceeding minor...moderate...and major flood stages
are listed for the valid time period.

CS values indicate the probability of reaching a flood category
based on current conditions.

HS values indicate the probability of reaching a flood category
based on historical or normal conditions.

When the value of CS is more than HS...the probability of
exceeding that level is higher than normal. When the value of CS is
less than HS...the probability of exceeding that level is lower
than normal.


...Table 1--Probabilities for minor...moderate and major flooding...
                    Valid Period:  03/06/2016 - 06/04/2016

                                       :    Current and Historical
                                       :     Chances of Exceeding
                                       :       Flood Categories
                                       :      as a Percentage (%)
                      Categorical      :
                   Flood Stages (ft)   :   Minor    Moderate   Major
Location           Minor   Mod   Major :  CS   HS   CS   HS   CS   HS
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:Grand River
Jackson             14.0   15.0   16.0 :  17   34    6   20   <5   13
Eaton Rapids         6.0    8.0    9.0 :  <5   <5   <5   <5   <5   <5
Dimondale           13.0   14.0   16.0 :  <5   <5   <5   <5   <5   <5
:Red Cedar River
Williamston          9.0   10.0   10.5 :  <5   <5   <5   <5   <5   <5
East Lansing         7.0   10.0   13.0 :  15   24   <5   <5   <5   <5
:Sycamore Creek
Holt                 8.0    9.0   10.0 :  37   35    8    8   <5   <5
:Grand River
Lansing             11.0   13.0   15.0 :  <5   12   <5   <5   <5   <5
Grand Ledge         11.0   13.0   15.0 :  <5   <5   <5   <5   <5   <5
Portland            12.0   14.0   16.0 :  <5   <5   <5   <5   <5   <5
:Looking Glass River
Eagle                7.0    9.0   11.0 :  37   51    7   16   <5   <5
:Maple River
Maple Rapids         9.0   11.0   13.0 :  28   39   <5   <5   <5   <5
:Grand River
Ionia               21.0   23.0   25.0 :   7   19   <5   <5   <5   <5
:Flat River
Smyrna               8.5    9.5   10.5 :  <5   <5   <5   <5   <5   <5
:Grand River
Lowell              15.0   18.0   20.0 :   9   23   <5   <5   <5   <5
:Thornapple River
Hastings             7.0    9.0   10.0 :  21   34   <5   <5   <5   <5
Caledonia           10.0   12.0   14.0 :   5   16   <5   <5   <5   <5
:Grand River
Ada                 20.0   22.0   25.0 :  <5   12   <5   <5   <5   <5
:Rogue River
Rockford             8.0   10.0   11.0 :   9   14   <5   <5   <5   <5
:Grand River
Grand Rapids        18.0   21.0   23.0 :  <5   14   <5   <5   <5   <5
:Pere Marquette River
Scottville           5.5    6.5    7.0 :  <5   <5   <5   <5   <5   <5
:White River
Whitehall            6.0    7.0    8.0 :   7   <5   <5   <5   <5   <5
:Muskegon River
Evart               12.0   13.0   14.0 :   8   23   <5    8   <5   <5
:Little Muskegon River
Morley               6.0    7.0    8.0 :  <5   <5   <5   <5   <5   <5
:Muskegon River
Croton               9.0   11.0   12.0 :  21   34   <5   <5   <5   <5
:Kalamazoo River
Marshall             8.0    9.0   10.0 :  <5   13   <5   10   <5    9
:Battle Creek
Battle Creek         4.0    5.0    6.0 :  <5   <5   <5   <5   <5   <5
:Kalamazoo River
Battle Creek         9.0   10.0   11.0 :  <5   <5   <5   <5   <5   <5
Comstock             9.0   10.0   11.0 :  <5   10   <5   <5   <5   <5
New Richmond        17.0   19.0   21.0 :  <5    8   <5   <5   <5   <5
:St Joseph River
Burlington           6.5    9.0   11.0 :   5   15   <5   <5   <5   <5
:Portage River
Vicksburg            5.0    7.0    8.0 :  32   36   <5   <5   <5   <5
:Chippewa River
Mt Pleasant          8.0   11.0   13.0 :  <5   12   <5   <5   <5   <5
:Pine River
Alma                 8.0   10.0   12.0 :  <5   11   <5   <5   <5   <5

Legend
CS = Conditional Simulation (Current Outlook)
HS = Historical Simulation
FT = Feet

In Table 2 below...the 95 through 5 percent columns indicate the
probability of exceeding the listed stage levels (FT) for the valid
time period.

...Table 2--Exceedance Probabilities...

                               Chance of Exceeding Stages
                                  at Specific Locations
                          Valid Period: 03/06/2016 - 06/04/2016
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Grand River
Jackson              11.1   11.3   12.1   12.9   13.6   14.6   15.6
Eaton Rapids          4.0    4.0    4.1    4.4    4.8    5.0    5.2
Dimondale             6.4    6.7    7.2    7.8    8.8    9.4    9.9
:Red Cedar River
Williamston           5.7    5.8    6.2    7.0    7.5    8.1    8.5
East Lansing          4.8    4.9    5.4    6.0    6.5    7.5    7.9
:Sycamore Creek
Holt                  6.2    6.5    7.0    7.6    8.4    8.9    9.1
:Grand River
Lansing               5.2    5.5    6.4    7.6    8.4   10.3   10.9
Grand Ledge           6.2    6.3    6.8    7.4    7.9    8.9    9.2
Portland              7.3    7.6    8.3    8.9    9.7   10.5   11.0
:Looking Glass River
Eagle                 4.9    5.0    5.7    6.5    7.8    8.8    9.4
:Maple River
Maple Rapids          7.4    7.5    8.0    8.6    9.1    9.5    9.6
:Grand River
Ionia                13.5   14.3   16.0   17.6   19.1   20.5   21.3
:Flat River
Smyrna                4.7    4.8    5.2    5.6    6.2    7.2    7.5
:Grand River
Lowell                8.3    8.6    9.9   11.0   12.6   14.6   15.8
:Thornapple River
Hastings              4.4    4.6    5.1    5.8    6.8    7.7    8.4
Caledonia             5.2    5.4    6.0    6.7    8.0    9.2   10.1
:Grand River
Ada                  11.5   11.9   13.7   15.3   17.1   18.6   20.0
:Rogue River
Rockford              5.3    5.5    5.9    6.3    7.0    7.9    8.4
:Grand River
Grand Rapids          7.4    7.9    9.9   12.4   14.7   16.3   17.7
:Pere Marquette River
Scottville            2.9    3.2    3.7    4.1    4.5    5.0    5.2
:White River
Whitehall             3.2    3.5    4.1    4.7    5.4    5.9    6.1
:Muskegon River
Evart                 9.3    9.5    9.8   10.4   11.1   11.7   12.2
:Little Muskegon River
Morley                2.9    3.0    3.3    3.9    4.4    4.7    5.0
:Muskegon River
Croton                7.1    7.4    7.6    8.1    8.8    9.6   10.1
:Kalamazoo River
Marshall              5.0    5.1    5.2    5.7    6.4    6.7    7.5
:Battle Creek
Battle Creek          1.4    1.4    1.6    1.8    2.1    2.4    2.6
:Kalamazoo River
Battle Creek          3.8    3.9    4.0    4.4    4.7    5.6    5.9
Comstock              4.9    5.0    5.2    5.8    6.3    7.8    8.0
New Richmond         12.8   13.1   13.6   14.3   14.8   15.8   16.2
:St Joseph River
Burlington            4.6    4.7    5.0    5.2    5.7    5.9    6.6
:Portage River
Vicksburg             4.3    4.4    4.5    4.8    5.1    5.2    5.3
:Chippewa River
Mt Pleasant           4.6    4.7    5.3    5.9    6.8    7.5    7.8
:Pine River
Alma                  4.2    4.4    5.0    5.6    6.3    7.7    7.9

In Table 3 below...the 95 through 5 percent columns indicate the
probability of falling below the listed stage levels (FT) for the
valid time period.

Table 3--Nonexceedance Probabilities...

                            Chance of Falling Below Stages
                                 at Specific Locations
                          Valid Period: 03/06/2016 - 06/04/2016
Location              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:Grand River
Jackson               9.9    9.8    9.5    9.4    9.2    8.9    8.9
Eaton Rapids          3.8    3.8    3.7    3.7    3.6    3.6    3.6
Dimondale             5.8    5.7    5.4    5.2    4.9    4.6    4.5
:Red Cedar River
Williamston           3.6    3.3    3.0    2.8    2.7    2.5    2.5
East Lansing          3.7    3.7    3.5    3.4    3.4    3.3    3.3
:Sycamore Creek
Holt                  3.6    3.5    3.4    3.4    3.4    3.3    3.3
:Grand River
Lansing               3.9    3.8    3.6    3.4    3.1    2.9    2.8
Grand Ledge           5.5    5.5    5.4    5.2    5.1    4.9    4.9
Portland              6.2    6.1    5.9    5.8    5.5    5.3    5.2
:Looking Glass River
Eagle                 3.7    3.4    3.1    3.0    2.9    2.7    2.6
:Maple River
Maple Rapids          4.8    4.6    4.0    3.6    3.3    3.0    2.9
:Grand River
Ionia                10.5   10.2    9.7    9.4    9.1    8.7    8.4
:Flat River
Smyrna                4.0    4.0    3.9    3.7    3.6    3.6    3.5
:Grand River
Lowell                6.7    6.5    6.2    6.0    5.7    5.4    5.1
:Thornapple River
Hastings              3.5    3.5    3.4    3.3    3.1    3.1    3.0
Caledonia             4.1    4.0    3.9    3.7    3.6    3.4    3.3
:Grand River
Ada                   8.9    8.5    8.0    7.5    7.0    6.5    5.9
:Rogue River
Rockford              4.5    4.4    4.3    4.2    4.0    3.9    3.9
:Grand River
Grand Rapids          4.4    4.1    3.8    3.6    3.5    3.4    3.2
:Pere Marquette River
Scottville            2.2    2.0    1.8    1.8    1.6    1.5    1.4
:White River
Whitehall             2.2    2.1    1.9    1.8    1.7    1.6    1.5
:Muskegon River
Evart                 8.1    8.0    7.8    7.6    7.3    7.2    7.2
:Little Muskegon River
Morley                2.4    2.4    2.4    2.3    2.3    2.3    2.2
:Muskegon River
Croton                6.0    5.9    5.6    5.4    5.1    5.0    4.9
:Kalamazoo River
Marshall              4.1    4.0    3.4    3.4    3.4    3.4    3.4
:Battle Creek
Battle Creek          1.1    1.1    1.0    1.0    0.9    0.9    0.8
:Kalamazoo River
Battle Creek          3.4    3.3    3.3    3.1    3.1    2.9    2.9
Comstock              4.5    4.4    4.3    4.2    4.1    4.0    3.9
New Richmond         11.7   11.5   11.2   10.9   10.6   10.3   10.0
:St Joseph River
Burlington            4.2    4.1    4.1    4.0    3.8    3.7    3.7
:Portage River
Vicksburg             3.9    3.9    3.9    3.8    3.7    3.6    3.5
:Chippewa River
Mt Pleasant           3.5    3.4    3.2    3.1    3.0    3.0    2.9
:Pine River
Alma                  2.5    2.3    2.0    1.8    1.6    1.5    1.3

These long-range probabilistic outlooks contain forecast values that
are calculated using multiple season scenarios from 30 or more years
of climatological data...including current conditions of the
river...soil moisture...snow cover...and 30 to 90 day long-range
outlooks of temperature and precipitation. By providing a range of
probabilities...the level of risk associated with long-range planning
decisions can be determined. These probabilistic forecasts are part
of the National Weather Service`s Advanced Hydrologic Prediction
Service.

Visit our web site weather.gov/grr for more weather and water
information.

This will be the last spring flood outlook for the season.  Long
range probabilistic outlooks such as those given in the above tables
are issued during the last week of each month.

$$

mjs





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